Two power wires shouldn't work or be necessary. On the kingkong micro cc3d (I think that's what you have) the connector on the end you're plugged into with the thicker power wires is intended for a sat receiver and puts out only 3.3v. Depending on which port is which the third wire is either main or flexi RX.
On most receivers all the power pins are connected. The manual for the receiver should say. Since that one specifically says the end port is power it's possible they're not connected and you have to put power in on that connector. If they are connected you're shorting 3.3v power to 5v power by connecting both cables.
I'd remove the cable to the 3 pin connector on the FC completely. Use a meter to see if the throttle (black,red,white) connector has power on it the way it's supposed to. Remember, the receiver is only powered by the battery, USB alone doesn't power it.
If the connector does have power with the battery connected but the receiver doesn't power up with it connected I'd try moving the power and ground pins from the throttle (black,red,white) connector and put them on the corresponding pins on the receiver power connector leaving just the white wire where it is.